首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
We have studied the effects of dopamine on the gill withdrawal reflex evoked by tactile siphon stimulation in the margine mollusc Aplysia. Physiological concentrations of dopamine (diluted in seawater) were perfused through the gill during siphon stimulation series. The amplitude of the reflex was potentiated by dopamine and habituation of the reflex was prevented. This occurred with no change in the activity evoked in central motor neurons. These results lead us to conclude that the dopaminergic motor neuron L9 is modulating habituation in the periphery and that the central nervous system facilitatory control of the peripheral nervous system may act via a dopaminergic pathway.  相似文献   

5.
Comparative examination of the scientific and philosophical ideas of Mikhail Mikhailovich Bakhtin and Aleksei Alekseevich Ukhtomskii is of interest from the standpoint of both the psychological theory of communication and the practice of psychological counseling, psychotherapy, and upbringing. Development of the applied areas of psychology poses the tasks of understanding the particular person and his individual problems and offering psychological assistance in the process of communication. To deal with these questions it is not sufficient to have scientific psychological training, i.e., knowledge of the general laws of personality development and communication; a capacity for personal communication as an aid to resolving human life problems is also necessary.  相似文献   

6.
7.
A theory for the static elastic behavior of blood vessels   总被引:1,自引:0,他引:1  
  相似文献   

8.
9.
10.
Homosexual behavior is defined as genital contact, genital manipulation or both between same-sex individuals. Available data indicate that this behavior is phylogenetically widespread among the anthropoid primates, but totally absent among prosimians. The majority of the 33 species that demonstrate homosexual behavior do so rarefy, but for a substantial number (N =12) it appears to be a more common pattern under free-ranging conditions. I summarize data on homosexual behavior as it relates to form, living condition, age, sex, social organization, and ecological context, and discuss hormonal, demographic, and sociosexual theories for primate homosexual behavior. Among adult primates, the behavior is not the product of abnormal excesses or deficiencies in androgens. Prenatal excesses of androgens may have some effect on the expression of female homosexual behavior, but these effects might vary over the life span, and data are equivocal at present. Demographic processes that result in skewed sex ratios can favor the expression of homosexual behavior in a population, which causes intraspecific variation. I examine several sociosexual explanations, including (a) proceptivity enhancement, (b) receptivity reduction, (c) dominance assertion, (d) practice for heterosexual copulation, (e) tension regulation, (f) reconciliation, and (g) alliance formation. An evolutionary scenario highlights the transformations this behavior underwent during the evolution of the anthropoid primates. I suggest exaptation as a theoretical framework for interpreting homosexual behavior and conclude that future consideration of sexual selection among primates should address homosexual components of this process.  相似文献   

11.
Homosexual behavior in primates: A review of evidence and theory   总被引:3,自引:0,他引:3  
Homosexual behavior is defined as genital contact, genital manipulation or both between same-sex individuals. Available data indicate that this behavior is phylogenetically widespread among the anthropoid primates, but totally absent among prosimians. The majority of the 33 species that demonstrate homosexual behavior do so rarefy, but for a substantial number (N =12) it appears to be a more common pattern under free-ranging conditions. I summarize data on homosexual behavior as it relates to form, living condition, age, sex, social organization, and ecological context, and discuss hormonal, demographic, and sociosexual theories for primate homosexual behavior. Among adult primates, the behavior is not the product of abnormal excesses or deficiencies in androgens. Prenatal excesses of androgens may have some effect on the expression of female homosexual behavior, but these effects might vary over the life span, and data are equivocal at present. Demographic processes that result in skewed sex ratios can favor the expression of homosexual behavior in a population, which causes intraspecific variation. I examine several sociosexual explanations, including (a) proceptivity enhancement, (b) receptivity reduction, (c) dominance assertion, (d) practice for heterosexual copulation, (e) tension regulation, (f) reconciliation, and (g) alliance formation. An evolutionary scenario highlights the transformations this behavior underwent during the evolution of the anthropoid primates. I suggest exaptation as a theoretical framework for interpreting homosexual behavior and conclude that future consideration of sexual selection among primates should address homosexual components of this process.  相似文献   

12.
13.
《CMAJ》1973,108(10):1209
  相似文献   

14.
15.
16.
A differential equation has been derived by A. Rapoport,Bull. Math. Biophysics,14, 159 (1952), giving the time course of the fraction of the population who have performed a given act. The general solution of this equation is obtained, some properties of the solution are deduced, and a special case presented in detail.  相似文献   

17.
A popular perspective on the social behavior of dogs in multiple-dog households sees the dogs' behavior as reflecting the sociobiological laws of the rigidly structured dominance hierarchy that has been described for wolf packs. This view suggests that aggression problems among dogs are natural expressions of conflict that arise whenever dominance status is in contention. One recommended solution has been for the owner to endorse and enforce a particular dominance hierarchy because, on the wolf pack model, aggression is minimized when the structure of the hierarchy is clear, strong, and stable. This article questions the validity of this perspective on 2 principal grounds. First, because it does not seem to occur in the wild, this article suggests the strong dominance hierarchy that has been described for wolves may be a by-product of captivity. If true, it implies that social behavior—even in wolves—may be a product more of environmental circumstances and contingencies than an instinctive directive. Second, because feral dogs do not exhibit the classic wolf-pack structure, the validity of the canid, social dominance hierarchy again comes into question. This article suggests that behavioral learning theory offers another perspective regarding the behavior of dogs and wolves in the wild or in captivity and offers an effective intervention for aggression problems.  相似文献   

18.
19.
Swelling of normal bovine articular cartilage equilibrated in NaCl solutions was dimensionally measured in thin strips of tissue. The ion-induced strains show that free swelling of articular cartilage is anisotropic and inhomogeneous. For the molar concentrations used, contraction increased linearly with concentration, defining a "coefficient of chemical contraction" (alpha c). Isometrically constrained specimens registered a rise in tensile force followed by stress relaxation. An extension of the biphasic theory incorporating this ion-induced strain is proposed. This theory can describe the equilibrium anisotropic swelling behavior of cartilage and explain the transient force history observed in the isometric experiment.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号